2 Answers
2

Transit routes. A route is a group of trips that are displayed to
riders as a single service. (The entire route)

GTFS Routes are equivalent to "Lines" in public transportation
systems. Routes are defined in the file routes.txt, and are made up
of one or more Trips - remember that a Trip occurs at a specific time
and so a Route is time independent.

In this model, a "trip" occurs along a "route". I think the simplest difference can been seen in the fact that a "route" has no directionality, it's just a line along which a transit vehicle travels. So if you look only at the route, you don't know which direction along the line anything is travelling: you need a "trip" to know that.

I guess you could say that a "route" exists on the ground. And a "trip" is what happens when the transit vehicle travels on along the route.

(note I had to use the word "when" in that last sentence... which indicates that a "trip" extends a "route" with some time information)